KR100573305B1 - High Density Polyethylene Films With Improved Barrier - Google Patents

Abstract

The present invention relates to high density polyethylene (HDPE) films with improved barrier properties. More specifically, the present invention relates to HDPE films containing hydrocarbon resins with improved water barrier properties. The present invention also relates to a masterbatch used to produce high density polyethylene films with improved barrier properties.

Description

High Density Polyethylene Films With Improved Barrier}             

The present invention relates to high density polyethylene (HDPE) films with improved barrier properties. More specifically, the present invention relates to HDPE films containing hydrocarbon resins having improved water barrier properties, and methods of making such films.

Polyolefins are useful plastic materials for producing a wide range of valuable products by a combination of strength, malleability, barrier properties, temperature resistance, optical properties, usability and low cost.

The use of terpenes and hydrogenated hydrocarbon resins as modifiers to convert polypropylene (PP) into oriented films is well known. Some of the properties resulting from the use of low molecular weight resin products in polypropylene films include good optical properties, improved processability in the manufacture of oriented films, good sealing properties, desirable mechanical and conversion properties.

The use of hydrocarbon resins (HCR) to improve the water barrier of oriented polypropylene is also known. The effect of the resin to improve the barrier properties is expected to be very dependent on the properties of the PP itself. These properties include the crystallinity of PP, the compatibility of the resin with the polypropylene amorphous region, and the glass transition of the amorphous region.

In addition, it is generally known that high levels of hydrocarbon resin are typically required to significantly improve the barrier properties of polypropylene films. However, adding resin at this level typically results in unoriented PP film too softly. In oriented polypropylene (OPP) films, the orientation imparted to the polymer offsets the negative effects of the resin on the malleability so that films with good mechanical properties can be produced at high loadings of hydrocarbon resins requiring improved barrier properties.

Due to differences in ethylene polymers and polypropylene in crystallinity levels, glass transition temperatures and amorphous properties (linear versus branched aliphatic structures), the effects of hydrocarbon resins in polyethylene films are strictly based on homologues of oriented polypropylene films. Cannot be expected. In addition, since most polyethylene films have a relatively low degree of molecular orientation compared to OPP films, the ability to incorporate hydrocarbon resins into polyethylene films at an effective level without destroying mechanical properties is of interest.

High Density Polyethylene (HDPE) is a linear homopolymer of ethylene that contains few branch points in the polymer chain. As a result of its regular structure, HDPE is a highly crystalline material having a peak crystal melting point near about 135 ° C. Various types of HDPE are characterized by the density of the material, which typically ranges from 0.940 to 0.965 (g / cc). Density is a measure of the crystallinity developed by the HDPE material, where higher density is associated with higher levels of crystallinity developed by the polymer. Mechanical properties and barrier properties are strongly influenced by the degree of crystallinity developed in the HDPE polymer.

Typically used in the manufacture of blow molded containers, such as milk bottles, molded products, lightweight consumer bags and garbage bags, and various types of film products.

One example of HDPE film products is the inner liner used to package cereal products. In this and similar packaging applications, the good barrier properties of HDPE as compared to unoriented PP or low density PE films make a very positive contribution to HDPE films. One type of barrier is to prevent the penetration of moisture into or out of the packaged food product.

There is a need for a method of incorporating various hydrocarbon resins into a high density polyethylene polymer (HDPE). There is also a need for a film that has good barrier properties but still has desirable mechanical properties so that the improved barrier properties of the film can be used in packaging film applications where useful. There is also a need for a very effective method for producing films of HDPE modified with hydrocarbon resins. It has been found that by adding various types of hydrocarbon resins to the HDPE polymer to form blends and forming films from the blend, superior packaging films with better moisture barrier properties can be produced than films made with HDPE polymer alone. These improved barrier films are useful in packaging applications where the reduced rate of moisture loss (or acquisition) increases the shelf life of the packaged material. On the contrary, by improving the barrier property of the HDPE film, it is possible to reduce the thickness of the film used to package the material and to lower the amount of packaging material required, and consequently to reduce the waste derived from the packaging film.

Summary of the Invention

The polyethylene film comprises about 3 to about 25 weight percent resin and about 97 to about 75 weight percent polyethylene. The resin has a weight average molecular weight (Mw) of less than about 10,000 Daltons, as determined using size exclusive chromatography (SEC) using polystyrene as a standard. Resins of Mw of less than 5000 Daltons are preferred, with resins having, for example, Mw of from about 500 Daltons to about 2000 Daltons being most preferred. The polyethylene has a density in the range of about 0.940 to about 0.970 g / cc as measured at 23 ° C. according to ASTM D1505. Barrierity improves density or crystallinity, preferably from about 0.940 to about 0.965 g / cc. Preferably, the film comprises about 3% to about 15% hydrocarbon resin.

The resin further comprises a hydrocarbon resin derived by thermally polymerizing an olefin feed rich in dicyclopentadiene (DCPD). Alternatively, the resin can be a hydrocarbon resin derived from the polymerization of a C9 hydrocarbon feed stream. Any of the above hydrocarbon resins may be fully or partially hydrogenated.

Alternatively, the hydrocarbon resin may be a resin derived from the polymerization of pure monomers, wherein the pure monomers are selected from the group consisting of styrene, α-methylstyrene, 4-methylstyrene and vinyltoluene.

Alternatively, the resin can be made from terpene olefins.

The polyethylene film may comprise a cast film or an orientation film. If the polyethylene film comprises an oriented film, it is a uniaxial or biaxially oriented film. The biaxially oriented film can be produced through a blown film method or a tenter frame orientation method.

The invention also relates to a masterbatch for the production of polyethylene films, to the preparation and use of the masterbatch, wherein the masterbatch comprises a resin and an ethylene polymer, the resin comprising polystyrene as the standard, size exclusion chromatography (SEC). ) Has a weight average molecular weight Mw of less than about 10,000 Daltons. Resins of Mw of less than 5000 Daltons are preferred, with resins having, for example, Mw of from about 500 to about 2000 Daltons being most preferred. The ethylene polymer has a density ranging from about 0.87 to about 0.965 measured at 23 ° C. according to ASTM D1505. The masterbatch also comprises about 2 to about 25 weight percent ethylene polymer and about 98 to about 75 weight percent resin. Preferably the masterbatch comprises about 70 to about 80 weight percent resin.

The invention also relates to a method of making a polyethylene film comprising a) blending polyethylene with a resin to form a blend, and b) extruding the blend to form a film. The film comprises about 3 to about 25 weight percent resin and about 97 to about 75 weight percent polyethylene, wherein the resin is about 10000 as measured using size exclusion chromatography (SEC) using polystyrene as a standard. It has a weight average molecular weight of less than Dalton, preferably less than 5000 Dalton, more preferably about 500 to about 2000 Dalton. The polyethylene has a density ranging from about 0.95 to about 0.965 g / cc as measured at 23 ° C. according to ASTM D1505.
Preferably, in the method of making a polyethylene film, the resin is a hydrocarbon resin and is added to the film in the form of a masterbatch, wherein the masterbatch comprises a hydrocarbon resin and an ethylene polymer and the hydrocarbon resin has an Mw of less than about 5000 Daltons. , The ethylene polymer has a density of about 0.87 to about 0.965 g / cc. Preferably, the masterbatch further comprises about 2 to 25 weight percent ethylene polymer and about 98 to about 75 weight percent hydrocarbon resin.

Most packaging films made of HDPE polymers are made by blown film or cast film methods. Lesser amounts are produced by the orientation method used to make OPP packaging films from polypropylene. The invention also relates to a method for improving the barrier properties of an HDPE film by incorporating a resin into the polymer blend. The invention further relates to a method of incorporating the resin into the HDPE film. Due to the low melt viscosity (relative to HDPE polymers) of the resins that can be used, blending the resins with HDPE during the film forming process is difficult and requires special addition techniques.

Various types of resins, including hydrocarbon resins, are added to the PP polymer blend and subsequently converted to an orientation film (OPP film) to improve the barrier of the modified film. Preferred resins for this use are fully hydrogenated products derived from the polymerization of various olefin hydrocarbon feeds. Examples of useful resin products include Regalite® R-125 resin (Hercules Incorporated, Middleburg, The Netherlands), mainly limonene, prepared by hydrogenating a polymerized product derived from a C9 hydrocarbon feed. Thermal polymerization of a feed rich in piccolit® C125 resin (Hercules Incorporated, Wilmington, Delaware), or dicyclopentadiene (DCPD), prepared by polymerizing a configured terpene feed Hydrogenated resins derived from e.g. Plastol® 140 Resin (Hercules Incorporated, Wilmington, DE) or Escoreez 5320 Resin (Exon Chemical corporation). In these cases, the resin has a special interaction with the amorphous portion of the PP polymer to which they are mixed, which reduces the ability of moisture to penetrate the polymer.

In addition, it is known that the use of hydrocarbon resins in OPP to improve barrier properties is handled with particular emphasis, wherein the orientation imparted during film production also greatly affects barrier properties. For example, oriented PP films typically exhibit 2.0-2.5 times better barrier properties than the barrier properties of the same PP polymer converted to non-oriented films. In addition to orienting the PP film, its strength and malleability in the stretching direction can be greatly improved so that brittleness effect by the addition of a significant amount of low molecular weight hydrocarbon resin can be overcome.

The use of hydrocarbon resins to improve the barrier properties of polypropylene converted to oriented films is known. However, the ability to obtain improved barrier properties by this method in non-oriented film structures is inferiorly limited, which incorporates significant amounts of resin into the non-oriented film, typically reducing the malleability to the unavailability of the film product. Because it is. The ability to improve the barrier properties of packaging films made from polymers other than HDPE or polypropylene is also inferiorly limited. The present invention discloses how to make useful HDPE packaging films with good barrier properties by incorporating hydrocarbon resins, and discloses an effective cost effective method of making these improved films.

HDPE packaging films with improved barrier properties can be prepared by melt blending hydrocarbon resins with HDPE polymer to form a blend and extruding the blend into a film. HDPE polymers useful in the present invention have a density in the range of about 0.940 to 0.970, with products in the range of about 0.955 to about 0.965 preferred. Similarly, the utility of HDPE in the present invention may have a melt index (190 ° C., 2.3 kg load, measured according to ASTM D-1238) in the range of about 0.1 to about 100 dg / min, but from about 0.5 to about 10.0. Polymers having a melt index of dg / min are most preferred for the extrusion process used to make the packaging films of the present invention. HDPE films can be produced by the cast film method or the blown film method which are commonly used to form HDPE packaging films. Other film processing techniques suitable for the production of HDPE packaging films (eg tenter frames) can also be used to make the films of the invention.

The usefulness of a hydrocarbon resin (HCR) useful in the present invention is a low molecular weight material induced by the polymerization of an olefin feed. These resins have a weight average molecular weight of less than about 10000 Daltons as measured using size exclusion chromatography (SEC) using polystyrene as a standard. Resins with Mw of less than 5000 Daltons are preferred, for example resins having Mw of from about 5000 to about 2000 Daltons are most preferred. The resin can be derived from crude olefin feeds derived from petroleum cracking, such as C5 olefin streams, C9 olefin streams, or DCPD rich olefin streams. Resins can also be prepared from terpene olefins such as limonene derived from citrus products. The resin may also be derived from a pure monomer stream, such as styrene or methyl styrene monomer. Aliphatic type resins are preferred. Preference is also given to hydrogenated resins with little residual aromatic character.

One of the advantages of the present invention is the production of packaging films having improved moisture barrier properties. Moisture barrier is measured according to ASTM E-96 method, where the film's water vapor transmission rate (MVTR) is tested at 100 ° F., 90% relative humidity. By modifying the HDPE film with a hydrocarbon resin, a 10-50% reduction in MVTR can be obtained compared to the unmodified film.

Since resins are typically brittle powdery materials with low Mw and low melt viscosity, it is difficult to add HDPE to them in the extrusion process during the manufacture of the film. An effective way of incorporating the resin into HDPE is to first form a masterbatch having a high concentration of resin mixed with the polymer carrier. This masterbatch can then be added to HDPE. The resin in the masterbatch is subsequently blended with the HDPE polymer during film extrusion. Preferred masterbatch formulations have as high a resin load as possible, have good handling properties, are well processed and must blend well when added to the HDPE polymer during the film forming step.

The present invention relates to improved films for packaging applications made from HDPE polymers which exhibit improved barrier properties over conventional films made only of HDPE. Improvements include incorporating an effective amount of hydrocarbon resin into the HDPE polymer to reduce water permeability through the film by at least about 10%, more typically about 20 to about 40%. These films are particularly useful for the packaging of food products that can be negatively affected by the loss of excess moisture under anhydrous conditions or by moisture gain under wet conditions. The invention also relates to a process for making these films by using resin masterbatch formulations that can be used to add hydrocarbon resin directly to the polymer during the film forming step.

The HDPE polymer used to make the films of the present invention may have a density in the range of about 0.940 to about 0.970, with HDPE polymer having a density in the range of about 0.955 to about 0.965. The density of the HDPE polymer is measured at 23 ° C. according to ASTM D1505. Barrier properties improve as the density or crystallinity of the HDPE polymer increases, which is why materials with the highest density are substantially preferred. HDPE polymers have a melt index (190 ° C., 2.3 kg load) in the range of about 0.1 to about 100 dg / min, but a polymer having a melt index of about 0.5 to about 10.0 dg / min is most preferred.

Any method suitable for making films from HDPE polymers can be used in the present invention. The film of the present invention can be produced by an extrusion cast method wherein the polymer is extruded through a slit die into a casting roll and the polymer is drawn to the final film thickness in the molten state. The film can also be produced by the blown film method, where the polymer is extruded into a cylindrical tube structure which is expanded to the final film thickness using internal air pressure inside the molten polymer tube to expand the dimensions. These are the most common processing methods for producing HDPE packaging films, and other modified film processing techniques, such as tenter orientation methods, may be used to produce the films of the present invention.

Resin products useful in the present invention may be any low molecular weight polymer derived by polymerizing an olefin feed, wherein the weight average molecular weight (Mw) of the material is less than about 20000 Daltons. Suitable resins have a Mw of less than about 10000 and hydrocarbon resins having a Mw of less than 5000 are preferred, for example from about 500 to about 2000 Mw of resin. The Mw of the resin is measured using size exclusion chromatography (SEC) using polystyrene as a standard. The resin can be derived from the crude olefin feed prepared in the petroleum cracking process. Examples of these crude olefin feeds include light olefin fractions having an average carbon number of 5 per olefin molecule (C5 feed) or cyclic olefins having an average carbon number of 9 olefin molecules (C9 feed). Resins made from DCPD rich olefin streams derived from ethylene cracking are also effective in the present invention. Useful resins can also be prepared from terpene olefins such as limonene derived from citrus products. Finally, resins derived from the polymerization of a pure monomer stream consisting of styrene, α-methylstyrene, 4-methylstyrene and vinyltoluene can be used in the present invention. In order to be compatible in HDPE, the resin must be essentially aliphatic, and for this reason hydrogenated resins with little residual aromatic properties are preferred. Fully hydrogenated resin products are preferred because of their light color and thermal stability.

One example of a resin useful in the present invention is a resin derived from catalytic hydrogenation after polymerization of the crude C9 feed stream. The C9 feed is defined as an olefin stream produced during petroleum cracking comprising a hydrocarbon olefin component having about 9 carbon atoms per molecule. Examples of olefins found in the C9 feed include, but are not limited to, styrene, α-methylstyrene, indene, various methyl substituted indenes, 4-methylstyrene, β-methylstyrene, ethylstyrene, among other olefins. The resulting resin product has aromatic character but can be converted to aliphatic type resin by catalytic hydrogenation. Hydrogenation means that the residual olefin groups of the resin and the aromatic units of the resin are converted to saturated species by reduction with hydrogen. The hydrogenation reaction can be carried out under a variety of conditions and is, for example, at a temperature in the range of about 150 to about 320 ° C. using hydrogen pressure of about 50 to about 2000 psi. More typically, hydrogenation will be performed at a temperature of about 200 to about 300 ° C. to produce the desired product. Typical catalysts for the hydrogenation of these resins would be Ni metals supported on a carrier such as carbon black. In this group, preferred types of products are resins in which at least about 90%, preferably at least about 95% of the aromatic units are hydrogenated. Examples of this type of resin are Regalit R-125 resins available from Hercules Incorporated, Middleburg, The Netherlands or Arcon® from Arakawa Chemical Co. ) P-125 resin.

Another example of a resin effective for this use is a resin derived from the polymerization of pure monomers such as styrene, α-methylstyrene, 4-methylstyrene, vinyltoluene or any combination thereof or similar pure monomer feed. The product produced by this polymerization has aromatic character but can be converted to aliphatic type resin by catalytic hydrogenation. The method used for hydrogenation of these resins is similar to the method suitable for hydrogenating resins derived from the C9 olefin feeds disclosed above. These resins, derived from hydrogenation of oligomers of pure monomers, can be hydrogenated to varying degrees, with about 20 to about 100% of the aromatic groups of the resin being reduced to saturated units. Preferably at least about 90% of the hydrogenated units must be hydrogenated, more preferably at least about 95%. Examples of these resins are Regalrez (R) 1139 resins or Regalez 1126 resins available from Hercules Incorporated.

Resins useful in the present invention can be derived from the polymerization of terpene olefins, for example cationic polymerization of monomers such as α-pinene, β-pinene or d-limonene. These resins are aliphatic type materials and hydrogenation is not necessary to obtain aliphatic properties. However, hydrogenation of the resin into saturated residual olefin groups can be carried out to produce resins with greater thermal stability that can similarly be used as part of the present invention. Examples of this type of resin include Piccolyte A-135 and Piccolate C-125 resins available from Hercules Incorporated.

Most preferred resins for the present invention are resins derived by thermally polymerizing an olefin feed rich in dicyclopentadiene (DCPD). This type of resin thermally reacts an olefin stream containing about 50 to about 100% DCPD at a temperature ranging from about 200 to about 325 ° C. to form a fully saturated material having a weight average molecular weight (Mw) of less than about 5000 Daltons. It can be prepared by preparing a resin product that can be hydrogenated. Hydrogenation of these resins is not necessary but very desirable to obtain low color DCPD resin products with good thermal stability. For example, a DCPD feed containing 85% DCPD may heat the DCPD to a temperature in the range of about 260 to about 300 ° C. for a suitable time, typically in the range of about 10 to about 200 minutes depending on the temperature, thereby producing a resin product. To a resin having a ring and ball (R & B) softening point in the range of about 100 to about 170 ° C., aliphatic properties, and a Mw of less than about 5000 as measured by ASTM D28-67 after stripping to remove hydrogenation and volatile components. can do. Examples of this type of resin are Plastol® 140 resins available from Hercules Incorporated or Escorez 5340 resins available from Exxon Chemical Corporation.

Films of the invention comprising blends of HDPE and hydrocarbon resins exhibit desirable barrier properties. One method of making the films of the present invention is to directly add hydrocarbon resin flakes or prills to HDPE mold pellets and convert the blends directly into the film using a film casting extruder as a mixing mechanism for melting and blending the two components. However, due to the brittle and powdery nature of hydrocarbon resins and the low viscosity of these materials at conventional plastic processing temperatures, this technique is difficult to implement for commercial use. Dust problems and extrusion problems associated with blend processing containing more than 5% hydrocarbon resin using a single screw extruder commonly used to make HDPE films make processing difficult.

Another method of preparing blends of hydrocarbon resins and HDPE is to melt the blends using an extruder or a batch mixing apparatus that can mix the ingredients in the desired proportions in the final film and mix the ingredients despite the large viscosity mismatch between the resin and HDPE. It is compounding. Typically this formulation is easily carried out to handle the powder. After blending the material, the melted blend is extruded through a multi-hole die and converted to solid pellet form by cooling and cutting the extrudate using typical techniques such as standard pelletization or underwater pelletization. These blended blends are suitable for extrusion and conversion to films under typical commercial conditions. The disadvantage of this technique is that all materials converted to films must be carried out through a compounding step which increases the cost. This method does not provide the film manufacturer with the flexibility to vary the amount of resin in the final film.

Another effective method of incorporating hydrocarbon resins into HDPE films is the preparation of masterbatches consisting of high concentrations of resin in a polymer carrier. By blending the resin with the polymer, powdering of the resin is minimized. In addition, the polymer blended with the resin increases the melt viscosity such that the masterbatch has a higher melt viscosity at the film processing temperature than the resin alone. By varying the viscosity in this manner, the masterbatch can be processed like a conventional polymer, which can be more easily blended into HDPE polymer during the film extrusion process than with hydrocarbon resin alone. An important aspect of the present invention is the development of novel masterbatch formulations that can be prepared in an economically effective manner for this type of use.

The hydrocarbon resin masterbatch of the present invention comprises about 60 to about 80% resin, which can be produced with high compounding efficiency. Preferably, the masterbatch is prepared with high blending efficiency containing 70 to 80% hydrocarbon resin. These improved masterbatches can be made using ethylene polymers mixed with hydrocarbon resins in the masterbatches.

In the masterbatch of the present invention, the hydrocarbon resin may be blended with polyolefin at a level of about 60 to about 80%, preferably about 70 to about 80%. Under these conditions, the relative rheological properties of both components are critical to obtaining good blending efficiency. For example, if polypropylene is the carrier, the mixing of the components cannot be obtained until the blend is about 165 ° C., which indicates the melting point of the polypropylene which is sufficiently flexible for the polymer to be processed. However, in ionicity, hydrocarbon resins have a very low melt viscosity compared to polypropylene. The physical behavior of blending materials is difficult because of rheological inconsistencies and requires additional mixing time and strength to allow the materials to mix.

Since low Mw hydrocarbon resins exhibit very severe viscosity / temperature dependencies, small changes in the temperature at which blending occurs significantly change the viscosity of the resin and increase the efficiency with which the resin can be blended with the polymer. Most resins useful for polyolefin modification have a softening point in the range of about 100 to about 140 ° C. In order to obtain a high compounding efficiency when producing a masterbatch containing 60% or more hydrocarbon resin, the crystalline polyolefin polymer used in the masterbatch is obtained using the ring & ball (R & B) softening point (ASTM D28-67) of the resin. Have a melting point not higher than about 10 ° C.). Within this limitation, preference is given to using ethylene polymers as carriers, where the ethylene polymers typically have a crystal melting point in the range of about 120 to about 140 ° C., and the density of the polymer or polymer blend in a masterbatch in the range of 0.87 to 0.965 g / cc. Has a crystallinity level exemplified by Polymers derived from 1-butene are also suitable because of their low melting point and other 1-olefin polymers or copolymers whose melting points range from about 100 to about 140 ° C. are also suitable.

The ability of resin / polymer blends to quickly crystallize into solid form is also a critical criterion for high blending efficiency. Polymers, such as polypropylene and polybutene, crystallize very slowly when blended into hydrocarbon resins at levels of about 60% or more, and consequently are difficult to form pellets from these blends at high rates. In contrast, polyethylene type crystallinity improves very rapidly in these blends even when the polymer concentration is as low as about 20% in the final blend. This rapid solidification promotes high compounding efficiency. As a result, it is desirable for a certain amount of polyethylene type crystallinity to be present in these improved resin masterbatches.

The preferred level of crystallinity improved by polyolefins in these resin masterbatches can be 10 to 70% based on the polymer and depends on both the end use for the masterbatches and the method used to pellet the masterbatches. When underwater pelletization is used, fast and complete solidification of the formulation into hard pellets is acceptable and desirable, and high crystalline polymers may be used. Polymers or polymer blends with medium crystallinity are preferred in strand pelletization, where the strands must improve resistance to drawing very quickly but the strands must have significant malleability to prevent fracture. In some applications, in order to obtain optimum barrier properties, it is desirable to maximize the crystallinity in the final blend and consequently the high crystallinity of the polymer used in the masterbatch.

The polymers used in these masterbatch formulations may have a melt index (MI) (190 ° C., 2.16 kg load) of 0.1 to 10 dg / min. Materials with higher MI are likely to mix with lower Mw resins. However, blends with lower MI polymers (higher Mw) have higher melt strength and higher melt viscosity, resulting in easier formation of strands or pellets and more when the masterbatch is blended with the polymer during film processing. Has good processing characteristics. Because of these conflicting limitations, the polymer used in the masterbatch has a MI of 0.5 to 5.0 dg / min.

Modified HDPE films of the invention can be made by introducing a resin into an HDPE polymer using any of the techniques disclosed above. A preferred method is the masterbatch method, wherein a blend containing 50 to 80% resin, preferably 60 to 80% resin, is added to the HDPE polymer to form a blend in which the film is prepared directly. The polymer used in the masterbatch does not degrade the barrier of the film, and as a result the preferred polymer is a crystalline polyethylene polymer having a density of at least about 0.91 g / cc.

HDPE films of the invention exhibit 10-50% better moisture barrier properties than comparative films that do not contain resins made from the same HDPE polymer under the same film forming conditions. Since some resins are more effective than others, the level of addition required depends on the desired barrier property improvement and resin type used.

Examples of hydrocarbon resins used with good effect on HDPE films include the trade names MBG 273 hydrogenated C9 resin, Regalez 1139 hydrogenated styrene-vinyl toluene copolymer resin, available from Hercules Incorporated, Middleburg, Netherlands; Plastolyn® 140 hydrogenated DCPD resins prepared by thermal polymerization of DCPD monomers, both of which are available from Hercules Incorporated, Wilmington, Delaware. Preferred resins are hydrogenated products derived from resin products formed by thermally polymerizing a DCPD feed. Examples of this preferred resin type include Platoline 140 resin sold by Hercules Incorporated and Escorez 5300 and Escorez 5320 resin sold by Exxon Chemical Company.

The hydrocarbon resin can be incorporated into the HDPE film at a level of 3 to 25%, but the preferred level of modification is to incorporate 3 to 15% of the hydrocarbon resin into the film. Increasing the resin content typically further improves the barrier properties of the film, but compromises some of the mechanical properties of the HDPE film. The optimal resin addition level is typically the balance between these two effects.

The following examples illustrate the invention and parts and percentages are by weight unless otherwise indicated.

Examples 1 to 3

In these examples, the hydrocarbon resin is an HDPE polymer (Alathon® M6580 HDPE sold by Lyondell Petrochemical Company) characterized by a density of 0.965 and a melt index of 9.0 dg / min. )). In Example 1 [20% Platoline 140 DCPD resin (commercially available from Hercules Incorporated) + 80% HDPE] blend was premixed and fed to Brabender D-6 counter rotating twin screw extruder It was. The extruder temperature was adjusted to 140-200 ° C. and the polymer blend was added at a rate that maintains little feed at the feed inlet. The blended blend was extruded through a two-hole die to form two strands which were cooled and pelletized in a water bath.

A similar 20% resin containing formulation was prepared in Example 2, wherein the hydrocarbon resin blended into HDPE was Regalez 1139 resin sold by Hercules Incorporated. Similarly, in Example 3, a hydrogenated C9 resin of 140 ° C. softening point made by Hercules Incorporated of the Netherlands and MBG 273 resin was blended to 20% level in HDPE.

Melting and mixing the HDPE polymer with the hydrocarbon resin is easy to obtain at this resin level and no problems have been observed in pelleting the blend. Because of the low resin content in these blends, they are not very effective resin masterbatches.

Comparative Example 1

In Comparative Example 1, cast film samples were thinned using a 3/4 "Brabender single screw extruder with a 24/1 L / D ratio to thin HDPE (available from Alaton M6580 HDPE, available from the Riondel Petrochemical Company). Prepared by extrusion into a film. The extruder was connected to a 6 "wide adjustable lip film die combined with a film casting device with a 5" diameter casting roll. The die ends of the film die and the extruder were heated to 250 ° C. and the extruder speed HDPE was drawn into a film having a thickness of about 1.75 mils by adjusting the speed of the casting rolls The temperature of the main casting rolls was controlled by circulating water at 80 ° C. through the rolls Cast having good appearance and suitable flatness Higher cast roll temperatures are required to produce HDPE films Samples of cast film made by processing HDPE under these conditions may be used for testing. Collected.

Examples 4-12

A series of modified HDPE cast films were prepared, wherein the hydrocarbon resin blends of Examples 1 to 3 were mixed with HDPE (Alaton M6580 HDPE, Liondel Petrochemical Company) to form a resin modified blend, which was tested. Cast directly into the film. In Example 4, 1 part of the Platoline 140 resin blend of Example 1 was mixed with 3 parts of HDPE and the blend (containing 5% resin) was made into a film having a thickness of about 1.75 mil using the same conditions as described in Comparative Example 1. Cast. In Example 5, a similar film was prepared, with the composition of the blend being 1 part of the hydrocarbon resin blend of Example 1 mixed with 1 part of HDPE (10% resin content). In Example 6, the film was made to have a higher 15% resin content by mixing 1 part HDPE and 3 parts Plastolline 140 compound of Example 1.

In Examples 7-9, a modified HDPE film was made into a film in the same manner as Examples 4-6, wherein the Regalez 1139 blend of Example 2 was used as a modifier to incorporate hydrocarbon resin into the HDPE film. Similarly the HDPE film modified in Examples 10-12 was prepared in the same manner as Examples 4-6, wherein the HDPE film was modified using the trade name MBG 273 resin masterbatch of Example 3.

There was no problem when the HDPE blends of Examples 4-12 were extruded as compared to casting films from HDPE alone. The resin blended well with HDPE and there was no negative problem with the extrusion result when the blend was extruded into a film. The cast film modified with Platoline 140 hydrogenated DCPD resin and the trade name MBG 273 hydrogenated C9 resin had a surface appearance and smoothness similar to or better than that of Comparative Example 1. The films of Examples 7-9 modified with Regalez 1139 resin showed a very rough surface texture but could be converted to a thin, pinhole free film. All films exhibit typical HDPE opacity and exhibit similar stiffness and malleability as unmodified HDPE films. The moisture barrier properties of these modified films are set forth in Table 1 below. Moisture barrier was measured on a film having a thickness in the range of 1.5 to 2.0 mils. Moisture barrier was improved with increasing film thickness and all comparisons were performed at the same film thickness.

Example number Hydrocarbon resin content MVTR (g, wheat / day, 100in ² ) Comparative Example 1 none 0.42 Example 4 5% Platoline 140 Resin 0.37 Example 5 10% Platoline 140 Resin 0.30 Example 6 15% Platoline 140 Resin 0.27 Example 7 5% Regales 1139 Resin 0.30 Example 8 10% Regales 1139 Resin 0.30 Example 9 15% Regales 1139 Resin 0.30 Example 10 5% MBG 273 Resin 0.35 Example 11 10% MBG 273 Resin 0.34 Example 12 15% MBG 273 Resin 0.32

Regalez 1139 resin was very effective at improving water barrier at low resin addition levels. No further barrier improvement was seen at resin addition levels above 5%. The film modified with the Platoline 140 hydrogenated DCPD resin had a very smooth surface appearance, significantly improved MVTR, and showed an increase in moisture barrier property when the resin content was above 5%. MBG 273 hydrogenated C9 resin was effective in improving the barrier properties of HDPE films but was less than Plastol 140 hydrogenated CDPD resin.

Examples 13-15

In Example 13, a physical blend of [50% Platoline 140 hydrogenated DCPD resin and 50% HDPE (Alaton M6580 HDPE, Liondel Petrochemical Company)] was used in the same manner as in Examples 1-3. Compounding was carried out using a D-6 twin screw extruder. The ingredients were effectively combined into a homogeneous melt blend. The extruder temperature was adjusted to minimize the melt temperature so that the blended extrudate had sufficient melt strength to form two strands that were subsequently pelletized. It can be noted that the extruded strand solidified into a hard form while still warm-hot almost immediately after entering the water bath. Rapid curing by rapid polyethylene crystallization It is necessary to minimize the cooling time and to keep the strands at a high temperature in order to prevent the strands from chipping and finally breaking the strands.

In Example 14, the masterbatch of Example 13 was mixed with HDPE at the 14% level while incorporating 7% Platoline 140 resin in the physical blend. This blend was cast into a 1.75 mil thick film in the manner described in Comparative Example 1. In Example 15 the masterbatch of Example 13 was mixed with HDPE at a level of 28% to incorporate 14% plastolin 140 resin into the blend and a cast film was prepared from this blend in the same manner as in Example 14.                 

The films of Examples 14 and 15 had a smooth appearance and exhibited excellent physical properties. The moisture barrier properties of these films were measured together with the films of Comparative Example 1 and Examples 4-6. These properties are shown in Table 2 below.

Example number Platoline 140 Resin (%) Resin MB Type MVTR (g, wheat / day, 100in ² ) Comparative Example 1 none - 0.42 Example 4 5% 20% level 0.35 Example 5 10% 20% level 0.28 Example 6 15% 20% level 0.25 Example 14 7% 50% level 0.31 Example 15 14% 50% level 0.28

The films of Examples 14 and 15 prepared using the high resin concentration masterbatch of Example 13 exhibited the same moisture barrier properties, good appearance, and good mechanical properties as modified films incorporated in HDPE at low concentrations of hydrocarbon resin. Indicated. There was no evidence that the Platoline 140 resin was insufficiently mixed with the HDPE resin of Example 14 or 15. Using a masterbatch with a high load of hydrocarbon resin is an effective way of incorporating the resin into the HDPE film.

Examples 16 and 17

In Examples 16 and 17, masterbatches containing high loads of hydrocarbon resins were prepared using a 32 mm idle twin screw extruder, a typical type of device used in the blending industry and suitable for the preparation of resin masterbatch formulations.

In Example 16, a blend consisting of [55% Platoline 140 resin and 45% HDPE (Alaton M6580 HDPE, Leonel Petrochemical Company)] was fed to the feed inlet of a Davis Stnadard D-Tex 32 mm twin screw extruder. Supplied to. Continuous gravity blending was performed using a weight scale blender supplied by Maguire Products. The extruder was operated in slow feed mode with the proper screw design and screw speed to effectively mix the material in one pass. The extruder temperature and screw speed were adjusted to maintain the exit melt temperature at about 170 ° C. The formulation efficiency was good and the resin and HDPE were blended as homogeneous extrudate at a rate of about 100 lbs / hr. The blended blend was extruded into four strands and subsequently pelletized. Physically mixing the components into a homogeneous melt can be performed at a good rate and the extruded strands solidified in such a way that they can be effectively pelletized with at least contact with the hot water bath. The total compounding rate is ultimately limited by the maximum speed of the pelletizer of about 70 to 80 lbs / hr. Attempts to prepare masterbatches having a 60% Platoline 140 resin concentration show that the physical blending of the components is very effective and the extruded strands can quickly solidify and easily pelletize. Blending at the 60% level is as effective as at the 55% level, but at higher resin levels the strands are brittle and brittle and destroy the product. At 55% minimum strand breaks occur.

In Example 16, the maximum resin level that can be effectively blended is defined by the method used to pellet the blend. Using underwater pelletization or watering pelletization eliminates the complexity of strand breakage, and resin masterbatches having a resin load of 60% or more can be produced with high production efficiency. The ease with which the hydrocarbon resin can be physically blended with the ethylene type polymer and coupled at the solidification rate of the very fast blended mixture is a critical criterion for obtaining high blending speeds and efficiencies.

In Example 17, the blend consisting of [27.5% Regalez 1139 resin, 27.5% Plastolrin 140 resin and 45% HDPE (Alaton M6580 HDPE, Leonel Petrochemical Company] was prepared in a similar manner to the masterbatch of Example 16. And similar results were obtained.

Comparative Examples 2 and 3

In Comparative Example 2, cast films were made from cast film grade HDPE polymers having a 0.960 density and 2.0 melt index (Alaton M6020 HDPE, Leonel Petrochemical Company). A film having a 2.0 mil thickness was prepared from this material by the same method as described in Comparative Example 1. Blown film grade HDPE resin with 0.960 density and 1.0 melt index (Alaton M6210 HDPE, Liondel Petrochemical Company) in Comparative Example 3 was cast into a 2.0 mil thick film in the same manner as Comparative Examples 1 and 2. .

Examples 18-21

In these examples, cast film grade HDPE polymers having a density of 0.960 and a 2.0 melt index (Alaton M6020 HDPE, Riondel Petrochemical Company) were subjected to 8% or 15% of the 55% hydrocarbon masterbatch described in Examples 16 and 17 ( Modified with 4.4% or 8.2% resin addition level). Films with a 2.0 mil thickness were cast from these blends in the same manner described in Comparative Examples 1-3. In Example 18 the plastolin 140 resin masterbatch of Example 16 was added to the cast film grade HDPE polymer at a level of 8%, and in Example 19 the level was increased to 15%.

In Example 20, the masterbatch of Example 17, consisting of both the same amount of Regalez 1139 resin and Platoline 140 resin, was added to the cast film grade HDPE polymer at the 8% level. In Example 21 the level of Example 17 masterbatch in the blend was increased to 15%.

There was no difficulty in casting the films of Examples 18-21. The film produced showed excellent appearance and mechanical properties. The moisture barrier properties of these films were measured along with their tensile properties, and the comparison results are shown in Table 3 below.

Comparative Example 2 Example 18 Example 19 Example 20 Example 21 HDPE (%) 100 92 85 92 85% Masterbatch type - Example 16 Example 16 Example 17 Example 17 MB level (%) - 8% 15% 8% 15% MVTR (g, wheat, day, 100 in ² ) 0.403 0.354 0.334 0.363 0.311 Tensile Modulus (Kpsi) Machine direction (MD) 111 106 120 112 117 Transverse (TD) 118 119 134 118 139 Yield Stress (Psi) MD 2967 3006 3057 3050 3014 TD 3075 3076 3210 3110 3440 Yield Strain (%) MD 12.7 13.6 12.5 12.6 11.9 TD 10.4 11.8 10.5 10.6 8.9

These results indicate that the hydrocarbon resin can be incorporated directly into the HDPE film by blending a resin masterbatch comprising at least 50% hydrocarbon resin with the HDPE polymer and mixing the resin masterbatch with HDPE during the film extrusion step.

The films of Examples 20 and 21 to which a masterbatch containing both Regalez 1139 resin and Platoline 140 resin were applied showed very good appearance and surface properties. The HDPE film modified with a masterbatch containing only comparative Legales 1139 resin showed irregular surface characteristics. The film of Example 21 modified to a higher 15% masterbatch level also exhibits moderately better barrier properties than the comparative Example 19 film modified to 15% masterbatch of Example 16 consisting of Plastollin 140 resin. .

Examples 22-25

In these examples, HDPE films are prepared in the same manner as Examples 18-21, except that blown film grade HDPE (Alaton M6210 HDPE polymer, Liondel Petrochemical Company) with a 0.960 density and 1.0 melt index is incorporated into the formulation. Used. The films were modified by adding the masterbatches of Examples 16 and 17 to HDPE, and a cast film having a 2.0 mil thickness was prepared in the same manner as the film of Example 18 Edge 21. The moisture barrier properties and tensile properties of these films are as set forth in Table 4 below and compared to the properties of the unmodified HDPE films of Comparative Example 3.

Comparative Example 3 Example 22 Example 23 Example 24 Example 25 HDPE (%) 100 92 85 92 85% Masterbatch type - Example 16 Example 16 Example 17 Example 17 MB level (%) - 8% 15% 8% 15% MVTR (g, wheat, day, 100 in ² ) 0.410 0.351 0.313 0.349 0.294 Tensile Modulus (Kpsi) MD 108 106 111 116 110 TD 125 115 138 125 140 Yield Stress (Psi) MD 3029 2984 3024 3054 3018 TD 3312 3245 3321 3237 3520 Yield Strain (%) MD 12.7 13.4 13.1 12.3 11.5 TD 9.7 11.1 10.3 9.9 8.5

The films of Examples 24 and 25 containing Regalez 1139 resin in addition to Platoline 140 DCPD resin exhibited good surface appearance. The film of Example 25 with a masterbatch addition level of 15% exhibits moderately better barrier properties than the film of Example 23 modified to a 15% level of plastolin 140 masterbatch of Example 16.

Examples 26-29 and Comparative Example 4

These examples illustrate the effective production of hydrocarbon resin masterbatches containing very high resin levels and the effective use of these masterbatches to produce modified HDPE films.

In Comparative Example 4, a mixture comprising [50% Platoline 140 DCPD resin and 50% polypropylene (PDC 1208 polypropylene, Montel USA, Inc.)] was spun Brabender D-6 model Formulated using a twin screw extruder. At this resin level, melt homogeneity was borderline and the blended strands barely had sufficient uniformity and continuity to be pelletized. When the pelletized blend was passed through two extruders to improve the homogeneity of the blend, strand uniformity increased significantly. However, even after two passes, pelletization of the formulation was difficult. The strands were still soft enough so that the pelletizer could not cut the strands cleanly, but rather the cuts produced rugged tears in which the strands stretched considerably, causing the pellets to become opaque white. Attempts to prepare similar masterbatches with 55% resin levels failed because improperly mixed and extruded blends solidified very late.

In Example 26 [75% Platoline 140 Resin, 10% HDPE (Alaton M6580 HDPE, Leonel Petrochemical Company) and 15% Polyethylene (Engage® 8440 Metallocene PE, Dow Chemical) Campus)] was formulated using the Brabender D-6 twin screw extruder under the same speed and similar conditions as in Comparative Example 4. The mixture of Example 26 was melt blended very effectively in the extruder and the melt homogeneity after one compounding pass was good. The extruded strand solidified much faster than in Comparative Example 4, and there was no problem of masterbatch pelletization. Extruded strands tend to be excessively brittle if cooled too much below about 60 ° C. because of their high resin content. Since the masterbatch of Example 26 solidifies very quickly but tends to be brittle if cooled too much, this type of product can be pelleted much more efficiently using a die face pelletization mechanism than strand pelletization.

In Example 27, a blend consisting of [78% Platoline 140 DCPD Resin + 22% Linear Low Density Polyethylene (Starmilex® 1016LF LLDPE, Netherlands DMS)] was used to obtain a Brabender D-6 twin screw extruder. In the same manner as in Example 26 and Comparative Example 4. StarMilex 1016LF LLDPE is an octene-based LLDPE polymer with 0.919 density and 1.1 melt index. Even at this high resin load, the mixing efficiency and extrudate homogeneity were very good, and the blended masterbatch could be stranded and pelletized. Even at the 78% resin level, the extrudate surprisingly had sufficient melt strength to pellet the strands, and the strands solidified quickly so that there was no problem with pelletizing. The final masterbatch blend was a crystalline clear pellet blend, where the pellets were very brittle but exhibited minimal powder or cracking properties. The masterbatch of Example 27 containing 78% hydrocarbon resin was prepared at the same rate as the masterbatch of Comparative Example 4, but with much less compounding difficulty than Comparative Example 4. In order to prepare a hydrocarbon resin masterbatch formulation containing at least about 50% resin, it is necessary to select a carrier polymer according to previously disclosed criteria so that the masterbatch can be formulated at a substantial rate.

A 2.0 mil thick HDPE film was cast from HDPE (Alaton M6020 HDPE, Liondel Petrochemical Company) in the same manner as described in Comparative Example 2. The HDPE film modified in Example 28 was mixed with 13% of the Platoline 140 masterbatch described in Example 26 and 87% HDPE and casting a 2.0 mil thick film directly from the blend in the same manner as described in Comparative Example 2. It was prepared by. Adding the 75% resin masterbatch of Example 26 to prepare the film of Example 28 did not have a negative effect on the extrusion of the HDPE polymer. The quality and processability of the film produced in Example 28 when making these films was the same or better than the results observed in the preparation of the unmodified Comparative Example 2 film.

Example 29 discloses another modified HDPE film prepared by blending HDPE with 13% of 78% Plastolline 140 resin masterbatch of Example 27 in the same manner as Example 28. Processing properties and film quality were not affected when the 78% resin masterbatch of Example 27 was added to the HDPE polymer to produce the film of Example 29. The hydrocarbon resin masterbatch of Example 27 was added to HDPE and the hydrocarbon resin was effectively dispersed in the HDPE film by extruding the cast film directly from the blend.

In both Examples 28 and 29, 10% level Plastoline 140 resin was effectively incorporated into the HDPE film by using the concentrated resin masterbatch of Examples 26 and 27. There was no negative effect on film formability by using a resin masterbatch having such a high resin load.

The examples presented herein are not intended to be limiting of the present application, but rather to represent some of certain embodiments of the present invention. Various modifications and variations can be made in the present invention without departing from the scope of the appended claims.

Claims (84)

An oriented polyethylene film comprising from 3 to 9 weight percent resin having a weight average molecular weight (Mw) of less than 10,000 Daltons, and from about 97 to about 91 weight percent polyethylene having a density ranging from about 0.94 to about 0.965 g / cc. , The resin provides a reduction in water vapor transmission rate (MVTR) measured by ASTM E-96 of about 10-50% compared to the same film without resin, The film is not crosslinked, Oriented polyethylene film. The method of claim 1, A polyethylene film wherein the resin has a weight average molecular weight (Mw) of less than 5000 Daltons. The method of claim 1, Polyethylene film wherein the film comprises about 3 to about 7% resin. The method of claim 1, A polyethylene film wherein the resin is induced by thermal polymerization of an olefin feed rich in dicyclopentadiene (DCPD). The method of claim 1, Polyethylene film wherein the resin is derived from polymerization of a C9 hydrocarbon feed stream. The method according to claim 4 or 5, Polyethylene film wherein the resin further comprises a hydrogenated resin. The method of claim 1, Polyethylene film wherein the resin is derived from polymerization of pure monomers. The method of claim 7, wherein Polyethylene film wherein the pure monomer is selected from the group consisting of styrene, α-methylstyrene, 4-methylstyrene and vinyltoluene. The method of claim 1, Polyethylene film wherein the resin is made from terpene olefins. The method of claim 9, A polyethylene film wherein terpene olefins comprise limonene. The method of claim 1, Polyethylene film, including cast film. The method of claim 10, Polyethylene film in which an oriented film contains a biaxially oriented film. delete The method of claim 12, Polyethylene film wherein the oriented film is produced via a blown film process. The method of claim 12, A polyethylene film in which a biaxially oriented film is produced through a tenter frame alignment process. delete delete delete delete delete delete delete delete delete delete delete delete a) blending polyethylene with a resin to form a blend; And b) extruding the blend to form a film, A method for producing the polyethylene film of claim 1. delete delete delete delete delete delete An oriented polyethylene film comprising 3 to 9 weight percent resin having a weight average molecular weight (Mw) of less than 10,000 Daltons, and about 97 to about 91 weight percent polyethylene having a density of about 0.95 to about 0.970 g / cc. The film is not crosslinked, Oriented polyethylene film. (a) a polyethylene having a density of about 0.94 to about 0.97 g / cc, and (b) a weight average molecular weight (Mw) of less than about 10,000 Daltons, consisting of a C5 olefin feed stream, a C9 feed stream, a terpene olefin, and a pure monomer. A polyethylene film comprising a resin derived from a crude olefin feed selected from the group, Wherein the film is oriented and substantially not crosslinked and has a decrease in water vapor transmission rate (MVTR) as measured by ASTM E-96 of 10-50% compared to similar films in the absence of resin. The method of claim 36, A polyethylene film wherein the resin has a weight average molecular weight (Mw) of less than 5000 Daltons. The method of claim 36, A polyethylene film wherein the resin is induced by thermal polymerization of an olefin feed rich in dicyclopentadiene (DCPD). The method of claim 36, Polyethylene film wherein the resin is derived by polymerizing a C9 hydrocarbon feed stream. The method of claim 36, Polyethylene film in which the resin is derived by polymerizing pure monomers. The method of claim 40, Polyethylene film wherein the pure monomer is selected from the group consisting of styrene, α-methylstyrene, 4-methylstyrene and vinyltoluene. The method of claim 36, Polyethylene film wherein the resin is derived from terpene olefins. The method of claim 42, A polyethylene film wherein terpene olefins comprise limonene. The method of claim 36, Polyethylene film, including cast film.  The method of claim 36, Polyethylene film produced by blown film process. The method of claim 36, Biaxially oriented polyethylene film. The method of claim 36, Polyethylene film biaxially oriented using a tenter frame orientation process. The method of claim 36, A polyethylene film in which the resin is present in an amount of 3 to 25% by weight and the polyethylene is present in an amount of 97 to 75% by weight. The method of claim 36, A polyethylene film in which the resin is present in an amount of 3 to 15% by weight and the polyethylene is present in an amount of 97 to 85% by weight. The method of claim 36, A polyethylene film wherein the resin is present in an amount of 3 to 12 weight percent and the polyethylene is present in an amount of 97 to 88 weight percent. The method of claim 36, Polyethylene film whose resin is an aliphatic resin. The method of claim 36, A polyethylene film wherein the resin is a hydrogenated resin. The method of claim 36, A polyethylene film wherein the resin is an aromatic resin having at least 90% of the hydrogenated aromatic moieties. The method of claim 53 wherein Polyethylene film wherein at least 95% of the aromatic moieties are hydrogenated. The method of claim 36, A polyethylene film having a thickness of about 0.001 to about 0.002 in. A polyethylene film comprising (a) a polyethylene having a density greater than 0.955 g / cc, and (b) a resin having a weight average molecular weight (Mw) of less than about 10,000 Daltons, Wherein the film is substantially not crosslinked and has a reduction in water vapor transmission rate (MVTR) measured by ASTM E-96 of at least about 10% compared to similar films in the absence of resin. The method of claim 56, wherein Polyethylene film having a density ranging from 0.955 to 0.965 g / cc. The method of claim 56, wherein Polyethylene film wherein the resin is derived from crude olefins selected from the group consisting of C5 olefin feed streams, C9 feed streams, terpene olefins, pure monomers and mixtures thereof. The method of claim 56, wherein A polyethylene film comprising resin in the range of about 3 to about 25 weight percent and polyethylene in the range of about 75 to about 97 weight percent. The method of claim 56, wherein A polyethylene film comprising resin in the range of about 3 to about 12 weight percent and polyethylene in the range of about 88 to about 97 weight percent. A polyethylene film comprising (a) a polyethylene having a density of about 0.94 to about 0.97 g / cc, and (b) a resin having a weight average molecular weight (Mw) of less than about 10,000 Daltons, Wherein the film comprises less than about 5 weight percent resin and is substantially crosslinked. 62. The method of claim 61, Polyethylene film having a reduction in water vapor transmission rate (MVTR) measured by ASTM E-96 of at least about 10% compared to similar films without resin. 62. The method of claim 61, Polyethylene film wherein the resin is derived from crude olefins selected from the group consisting of C5 olefin feed streams, C9 feed streams, terpene olefins, pure monomers and mixtures thereof. 62. The method of claim 61, Polyethylene film comprising polyethylene in the range of about 95 to about 97 weight percent. Polyethylene film containing. (a) a polyethylene having a density of about 0.94 to about 0.97 g / cc, and (b) a weight average molecular weight (Mw) of less than about 10,000 Daltons, consisting of a C5 olefin feed stream, a C9 feed stream, a terpene olefin, and a pure monomer. A polyethylene film comprising a resin derived from a crude olefin selected from the group, The polyethylene film is oriented and substantially not crosslinked and is prepared using a masterbatch comprising the polyethylene and the resin, Wherein the polyethylene film has a decrease in water vapor transmission rate (MVTR) as measured by ASTM E-96 of 10 to 50% compared to a similar film in the absence of resin. Polyethylene film. 66. The method of claim 65, A polyethylene film wherein the resin has a weight average molecular weight (Mw) of less than 5000 Daltons. 66. The method of claim 65, A polyethylene film wherein the resin is induced by thermal polymerization of an olefin feed rich in dicyclopentadiene (DCPD). 66. The method of claim 65, Polyethylene film wherein the resin is derived by polymerizing a C9 hydrocarbon feed stream. 66. The method of claim 65, Polyethylene film in which the resin is derived by polymerizing pure monomers. The method of claim 69, Polyethylene film wherein the pure monomer is selected from the group consisting of styrene, α-methylstyrene, 4-methylstyrene and vinyltoluene. 66. The method of claim 65, Polyethylene film wherein the resin is derived from terpene olefins. The method of claim 71 wherein A polyethylene film wherein terpene olefins comprise limonene. 66. The method of claim 65, Polyethylene film, including cast film.  66. The method of claim 65, Polyethylene film produced by blown film process. 66. The method of claim 65, Biaxially oriented polyethylene film. 66. The method of claim 65, Polyethylene film biaxially oriented using a tenter frame orientation process. 66. The method of claim 65, A polyethylene film in which the resin is present in an amount of 3 to 25% by weight and the polyethylene is present in an amount of 97 to 75% by weight. 66. The method of claim 65, A polyethylene film in which the resin is present in an amount of 3 to 15% by weight and the polyethylene is present in an amount of 97 to 85% by weight. 66. The method of claim 65, A polyethylene film wherein the resin is present in an amount of 3 to 12 weight percent and the polyethylene is present in an amount of 97 to 88 weight percent. 66. The method of claim 65, Polyethylene film whose resin is an aliphatic resin. 66. The method of claim 65, A polyethylene film wherein the resin is a hydrogenated resin. 66. The method of claim 65, A polyethylene film wherein the resin is an aromatic resin having at least 90% of the hydrogenated aromatic moieties. 83. The method of claim 82, Polyethylene film wherein at least 95% of the aromatic moieties are hydrogenated. 66. The method of claim 65, A polyethylene film having a thickness of about 0.001 to about 0.002 in.